. The anatomy of the human body. Human anatomy; Anatomy. enters an ovoid cavity (a b t, fig. 259) called the vestibule. The vestible is the centre of the internal ear, and forms an intermediate cavity or passage (fo- rum fodinae metallicas, Vesalius) between the semicircular canals (o p q,fig. 258), which are on its outer side, and the cochlea (?), which is to its inner side. It is situated in a line with the axis fg of the internal auditory meatus. It is remark- able for having a great number of both large and smaU openings into it. The large openings are seven in number: the first is the fen
. The anatomy of the human body. Human anatomy; Anatomy. enters an ovoid cavity (a b t, fig. 259) called the vestibule. The vestible is the centre of the internal ear, and forms an intermediate cavity or passage (fo- rum fodinae metallicas, Vesalius) between the semicircular canals (o p q,fig. 258), which are on its outer side, and the cochlea (?), which is to its inner side. It is situated in a line with the axis fg of the internal auditory meatus. It is remark- able for having a great number of both large and smaU openings into it. The large openings are seven in number: the first is the fenestra ovalis (/, figs. 258, 261), which would establish a free communication between the vestibule of the tympa- num if it were not for the base of the stapes, which closes it hermetically, as we may be convinced by examining it from the vestibule, when the stapes remains m its place.* There are>e openings (,o'p' q',fig. 259 ; o' a', fig. 261) for the three semicircular canals; p- 259 and the seventh is the orifice {t) of the vestibular scala of the cochlea. In macerated bones we find, besides, an eighth opening, situated below the fenestra ovalis, having an oblong shape, and leading into the highest part of the fenestra ro- tunda. Of the small openings, the first is the orifice (r, fig. 259) of the aqueduct of the vestibule, which opens upon the posterior wall of this cavity to the inner side of the common opening for the two rw ,,, .V , f, •., vertical semicircular canals {i. e., in the recessus Osseons labvnnth of the left side. .v^iiiv^i. , r ^\. iui* Magnified two diameters. sulciformis). The aqueduct of the vestibule turns a short distance around that common opening, and then, bending at a right angle, ter- minates upon the posterior surface of the petrous portion of the temporal bone by an orifice already described (see Osteology). The other small openings in the vestibule are foramina for the passage of vessels and nerves ; they form the macula cribrosa, which
Size: 2148px × 1163px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1800, booksubjectanatomy, booksubjecthumananatomy
